日本七鳃鳗富含半胱氨酸RGD蛋白Lj-RGD1抑制血小板聚集及抗血管新生功能

Lj-RGD1来源于日本七鳃鳗口腔腺,富含半胱氨酸并具有RGD(Arg-Gly-Asp)模体.为了验证Lj-RGD1是否具有抑制血小板聚集、抗血管新生等去整合素样典型功能,本文对七鳃鳗Lj-RGD1进行了克隆表达及活性测定.提取七鳃鳗口腔腺中总RNA进行RT-PCR扩增,获得Lj-RGD1的420 bp cDNA.对其进行克隆、表达及组氨酸亲和层析纯化后,获得分子量为169 kD的可溶性蛋白rLj-RGD1.活性测定结果显示,rLj-RGD1呈剂量依赖方式抑制ADP诱导的兔血小板聚集,IC50为123 μmol/L;血管新生抑制实验结果表明,rLj-RGD1能够诱导ECV304细胞凋亡,抑制ECV304细胞增殖和管状物形成,并呈剂量依赖性方式抑制鸡胚胎绒毛尿囊膜（chorioallantoic membrane,CAM）血管新生.由此可见,Lj-RGD1具有去整合素样生物活性,在血栓或血管异常新生类疾病治疗中具有应用前景.     

血小板反应性增高患者相关指标的检测与分析

目的:探讨反应性血小板增高患者凝血指标及血小板聚集功能指标变化规律。方法:143例血小板反应性增高患者和65例对照者同时检测血小板聚集功能、抗凝血酶活性(AT-Ⅲ)、凝血酶原时间(PT)和活化部分凝血活酶时间(APTT),并统计分析。结果:血小板反应性增高常见于肿瘤、肺炎、外伤患者;血小板反应性增高组患者AT-Ⅲ、PT和APTT与对照组无差异,但患者血小板聚集功能显著高于对照组。结论:血小板反应性增高患者血小板聚集功能增强,建议定期监测血小板聚集功能,必要时用抗血小板聚集药预防。     

Impact of chicory inclusion in a cereal-based diet on digestibility,organ size and faecal microbiota in growing pigs

A total of 30 7-week-old pigs were used to evaluate the effects of chicory inclusion on digestibility, digestive organ size and faecal microbiota. Five diets were formulated: a cereal-based control diet and four diets with inclusion of 80 and 160 g/kg chicory forage (CF80 and CF160), 80 g/kg chicory root (CR80) and a mix of 80 g/kg forage and 80 g/kg chicory root (CFR). Generally, the pigs showed a high growth rate and feed intake, and no differences between the different diets were observed. The coefficients of total tract apparent digestibility (CTTAD) of energy, organic matter and CP did not differ between the control and CF80, whereas they were impaired in diet CF160. The CTTAD of non-starch polysaccharides and especially the uronic acids were higher (P < 0.05) with chicory inclusion, with highest (P < 0.05) values for diet CF160. Coliform counts were lower and lactobacilli : coliform ratio was higher (P < 0.05) in diet CFR than in the control. Global microbial composition was investigated by terminal restriction fragment length polymorphism combined with cloning and sequencing. Analysis of gut microbiota pattern revealed two major clusters where diet CF160 differed from the control and CR80 diet. Chicory forage diets were correlated with an increased relative abundance of one species related to Prevotella and decreased abundance of two other species related to Prevotella. For diet CFR, the relative abundance of Lactobacillus johnsonii was higher than in the other diets. This study shows that both chicory forage and root can be used as fibre sources in pig nutrition and that they modulate the composition of the gut microbiota differently.     

Impact of dietary betaine and conjugated linoleic acid on insulin sensitivity,protein and fat metabolism of obese pigs

To determine possible mechanisms of action that might explain the nutrient partitioning effect of betaine and conjugated linoleic acid (CLA) in Iberian pigs and to address potential adverse effects, twenty gilts were restrictively fed from 20 to 50 kg BW Control, 0.5% betaine, 1% CLA or 0.5% betaine + 1% CLA diets. Serum hormones and metabolites profile were determined at 30 kg BW and an oral glucose test was performed before slaughter. Pigs were slaughtered at 50 kg BW and livers were obtained for chemical and histological analysis. Decreased serum urea in pigs fed betaine and betaine + CLA diets (11%; P = 0.0001) indicated a more efficient N utilization. The increase in serum triacylglycerol (58% and 28%, respectively; P = 0.0098) indicated that CLA and betaine + CLA could have reduced adipose tissue triacylglycerol synthesis from preformed fatty acids. Serum glucose, low-density lipoprotein (LDL) cholesterol and non-esterified fatty acids were unaffected. CLA and betaine + CLA altered serum lipids profile, although liver of pigs fed CLA diet presented no histopathological changes and triglyceride content was not different from Control pigs. Compared with controls, serum growth hormone decreased (20% to 23%; P = 0.0209) for all treatments. Although serum insulin increased in CLA, and especially in betaine + CLA pigs (28% and 83%; P = 0.0001), indices of insulin resistance were unaffected. In conclusion, CLA, and especially betaine + CLA, induced changes in biochemical parameters and hormones that may partially explain a nutrient partitioning effect in young pigs. Nevertheless, they exhibited weak, although detrimental, effects on blood lipids. Moreover, although livers were chemically and histologically normal, pigs fed CLA diet challenged with a glucose load had higher serum glucose than controls.     

The effect of chitooligosaccharide supplementation on intestinal morphology,selected microbial populations,volatile fatty acid concentrations and immune gene expression in the weaned pig

An experiment (complete randomised design) was conducted to investigate the effects of supplementing different molecular weights (MW) of chitooligosaccharide (COS) on intestinal morphology, selected microbial populations, volatile fatty acid (VFA) concentrations and the immune status of the weaned pig. A total of 28 piglets (24 days of age, 9.1 kg (± s.d. 0.80) live weight) were assigned to one of four dietary treatments for 8 days and then sacrificed. The treatments were (1) control diet (0 ppm COS), (2) control diet plus 5 to 10 kDa COS, (3) control diet plus 10 to 50 kDa COS and (4) control diet plus 50 to 100 kDa COS. The COS was included in dietary treatments at a rate of 250 mg/kg. Tissue samples were taken from the duodenum, jejunum and ileum for morphological measurements. Digesta samples were taken from the proximal colon to measure lactobacilli and Escherichia coli populations and digesta samples were taken from the caecum and proximal colon for VFA analysis. Gene expression levels for specific cytokines were investigated in colonic tissue of the pig. Supplementation of different MW of COS had no significant effect on pig performance during the post-weaning period (days 0 to 8; P > 0.05). The inclusion of COS at all MW in the diet significantly reduced faecal scores compared with the control treatment (P < 0.01). Pigs fed the 10 to 50 kDa COS had a higher villous height (P < 0.05) and villous height : crypt depth ratio (P < 0.05) in the duodenum and the jejunum compared with the control treatment. Pigs fed the 5 to 10 kDa COS had a lower lactobacilli population (P < 0.05) and E. coli population (P < 0.05) in the colon compared with the control group. Pigs offered the 5 to 10 kDa COS had significantly lower levels of acetic acid and valeric acid compared with the control group (P < 0.05). The inclusion of different MW of COS had no significant effect on the expression of the cytokines tumour necrosis factor-α, Interleukin (IL)-6, IL-8 and IL-10 in the gastro-intestinal tract of the weaned pig. The current results indicate that a lower MW of 5 to 10 kDa COS possessed an antibacterial activity, while the higher MW of 10 to 50 kDa was optimum for enhancing the intestinal structure.     

Serum cortisol and haematological,biochemical and antioxidant enzyme variables in horse blood sampled in a slaughterhouse lairage,immediately before stunning and during exsanguination

The aim of the study was to determine changes of serum cortisol and biochemical, haematological and antioxidant enzyme variables in the blood of horses sampled during the pre-slaughter period (in the lairage and in the stunning box) and during exsanguination. A total of 24 Slovenian warm-blooded horses were observed. Blood samples for determination of serum cortisol and biochemical, haematological (red blood cell count, haematocrit, haemaglobin concentration) and antioxidant enzyme (whole blood superoxide dismutase and glutathione peroxidase) variables were collected by venipuncture of the left jugular vein in the lairage pen, 60 min before stunning (lairage) and immediately before stunning (stunning box). At exsanguination, blood samples were collected from the wound at the time of jugular vein sticking. During blood collection in the lairage pen and in the stunning box, horses were gently restrained with a halter. They were stunned using a penetrating captive bolt pistol impelled by air and were bled by jugular vein sticking. Horses were physically active in the lairage pen and in the race before entering the stunning box. After stunning, the horses showed paddling movements with their legs. In horses, the plasma lactate and glucose concentrations, the serum potassium concentration, the activities of the serum muscle enzymes aspartate aminotransferase and creatine kinase, and values of most of the other biochemical (Table 1) and haematological variables (Table 2), were significantly (P < 0.05) higher at exsanguination, than in blood sampled while they were in the lairage and in the stunning box. The serum concentrations of cortisol and chloride and the activities of alanine aminotransferase and antioxidant enzymes were not significantly different between the pre-slaughter period and exsanguination. All selected blood variables were not significantly different between the lairge and the stunning box sampling time, indicating no physiological stress responses of the investigated horses to stressors, such as novelty of the pre-slaughter environment and handling, present in the slaughterhouse between the lairage and the stunning box. However, the significantly higher values, at exsanguination, for the plasma lactate and glucose concentrations, serum muscle enzyme activities and haematological variables, than during the pre-slaughter period, might partially be attributed to stimulation of the sympathetic nervous system, caused by stunning and bleeding.     

Blood and tissue fatty acid compositions,lipoprotein levels,performance and meat flavor of broilers fed fish oil: changes in the pre- and post-withdrawal design

Administration of fish oil (FO) in broiler diets can elevate α-linolenic acid (ALA), eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) levels, which are protective against cardiovascular disease. However, optimization based solely on n-3 polyunsaturated fatty acid (n-3 PUFA) enrichment in chicken meat could lead to lower meat quality, unless the withdrawal period (plan) is applied for 1 week. The present study investigated whether the incorporation of FO in the diet for 32 days followed by its withdrawal for 1 week affected blood lipid profiles, lipoprotein particles, performance and meat flavor in male broiler chickens. Two hundred and forty birds (1-day-old, Ross 308) were assigned to 1 of 4 dietary groups: 0%, 1%, 2% or 3% FO with four replicates. Broilers were fed for 49 days according to a 4-phase feeding program. The experimental phase comprised day 11 to 42, and FO was removed on day 42. Blood samples were collected during the pre- and post-withdrawal period after the recordings before slaughter. The FO groups demonstrated decreased low-density lipoprotein (LDL) and increased high-density lipoprotein levels on day 42 (P < 0.01); however, these values were not significant after design withdrawal. Diet supplementation with FO elevated the blood levels of palmitic acid (C16:0) and n-3 PUFAs, especially long-chain (LC) PUFAs (EPA, C20:5n-3 and DHA, C22:6n-3), and caused a decline in the level of arachidonic acid (AA, C20:4n-6; P < 0.05). Application of a one-week withdrawal period resulted in a decrease in (P < 0.05) linoleic acid (C18:2n-6) and an increase in the level of AA, unlike their amounts on day 42. Although blood and tissue LC n-3 PUFA levels on day 49 were significantly higher in the FO groups compared with the control, they demonstrated a substantial decrease on day 49 compared with day 42. The best results, mainly the lowest n-6/n-3 fatty acids (FAs) and feed conversion ratio (FCRs), were observed for 3% FO (group T4), even after institution of the withdrawal design. Degradation of total n-3 FAs deposited in tissues occurred after instituting the withdrawal plan diet, but deposited levels of EPA and DHA in tissues could ensure omega-3 enrichment of broiler meat in groups 3 and 4. On the basis of the dissatisfaction of the panelists toward group 4 meats (scored as near to acceptable) and their satisfaction with cooked samples of T3 (scored as good), group 3 meats were selected as good-quality n-3-enriched broiler meat.     

The solution structure of the adhesion protein Bd37 from Babesia divergens reveals structural homology with eukaryotic proteins involved in membrane trafficking

Babesia divergens is the Apicomplexa agent of the bovine babesiosis in Europe: this infection leads to growth and lactation decrease, so that economical losses due to this parasite are sufficient to require the development of a vaccine. The major surface antigen of B. divergens has been described as a 37 kDa protein glycosyl phosphatidyl inositol (GPI)-anchored at the surface of the merozoite. The immuno-prophylactic potential of Bd37 has been demonstrated, and we present here the high-resolution solution structure of the 27 kDa structured core of Bd37 (Δ-Bd37) using NMR spectroscopy. A model for the whole protein has been obtained using additional small angle X-ray scattering (SAXS) data. The knowledge of the 3D structure of Bd37 allowed the precise epitope mapping of antibodies on its surface. Interestingly, the geometry of Δ-Bd37 reveals an intriguing similarity with the exocyst subunit Exo84p C-terminal region, an eukaryotic protein that has a direct implication in vesicle trafficking. This strongly suggests that Apicomplexa have developed in parallel molecular machines similar in structure and function to the ones used for endo- and exocytosis in eukaryotic cells.     

Unloading oxygen in a capillary vessel under a pathological condition

In this work, we study theoretically the unloading of oxygen from a hemoglobin molecule to the wall of a typical capillary vessel, considering that the hemoglobin under pathological conditions, obeys the rheological Maxwell model. Based on recent experimental evidences in hypertension, we consider that the red blood cells (RBCs) are composed by a single continuous medium in contrast with the classical particulate or discrete RBC models, which are only valid under normal physiological conditions. The analysis considers the hemodynamic interactions between the plasma and the hemoglobin, both circulating in a long horizontal capillary. We apply numerical and analytical methods to obtain the main fluid-dynamic characteristics for both fluids in the limit of low Reynolds and Womersley numbers. A diffusion boundary layer formulation for the oxygen transport in the combined plasma-hemoglobin core region is presented. The main aspects derived are the time and spatial evolution of the membrane. The hemoglobin and plasma velocities and the pressure distributions are shown. For the oxygen unloading the results are the oxy-hemoglobin saturation, the oxygen flux and the oxygen concentration in the cell-free plasma layer. The volume fraction of red blood cells and the Strouhal number have a great influence on the hemodynamic interactions.